Using hierarchical identity based cryptography for authenticating outbound mail
A hierarchical identity based cryptographic system (“HIBC”) is integrated with the domain name system (“DNS”). A private key is assigned to each of the top level domain name authorities responsible for assigning the top level domain names (e.g., .net, .com, etc.). The private key is generated according to an HIBC system, wherein the corresponding public key is based on the identity of the particular domain authority. When user requests a domain name from one of the top level domain name authorities, the user is issued a private key that is generated by the top level domain authority using its private key and the identity of the user according to the particular HIBC system implemented. The user's corresponding public key can be derived from the identity of the user and the public key of the top level domain name authority. Similarly, when the user adds servers and accounts to the users domain, the user can generate private keys for the servers and accounts using the users private key according to the particular HIBC system. Later, emails originating from the users domain can be authenticated by recipients using the public key associated with the top level domain name authority.
1. A method for authenticating electronic mail using hierarchical identity-based cryptography, comprising:
in a hierarchy associated with a domain name service, wherein a first domain resides above a second domain, for the second domain, generating a second public key and second private key pair, wherein the second public key is derived using the domain name service and the second private key is generated using a first private key associated with the first domain;
for an email server within the second domain, generating a third private key based on the first private key of the first domain;
for each of a plurality of users, generating a respective public key and private key pair, wherein a respective public key for a user is derived from an associated user name and a respective private key for a user is generated using the third private key;
receiving an email message from a sender to a recipient, wherein the email message is signed using a corresponding private key of the sender; and
authenticating the sender using a corresponding public key of the sender, wherein the public key of the sender is derived using the domain name service.
2. The method of claim 1 , wherein each public key can be determined using a public key of a top level domain name authority using a hierarchical identity based cryptographic system.
3. The method of claim 2 wherein the top level domain name authority is one com., org, .net, .gov of.edu, .mil, .biz, or .name.
4. The method of claim 2 , wherein the top level domain name authority corresponds to a country code top level domain name.
5. The method of claim 1 , wherein the sender is associated with the email server, and wherein the corresponding private key of the sender is the third private key.
6. The method of claim 5 , wherein the email server is authenticated using a corresponding public key of the email server derived using the domain name service.
7. The method of claim 5 , wherein the email server is authenticated by an email server of the recipient.
8. The method of claim 1 , wherein the third private key is generated using a hierarchical identity based cryptographic system.